Studies are in progress to determine the role of cytochrome P-450 in ergot alkaloid biosynthesis. Microsomes from Claviceps sp. SD 58 and PRL 1980 catalyze the conversion of agroclavine to elymoclavine. The activity correlates well with the time course of alkaloid production. Preliminary experiments to purify the cytochrome P-450 and NADPH-cytochrome c reductase components have been carried out. Reconstitution of activity was not accomplished. Addition of NADPH-cytochrome c reductase to microsomes increased the conversion of agroclavine to elymoclavine. Current research involves the determination of the difference spectrum for agroclavine binding to cytochrome P-450 and modification of the procedures to give fractions active in reconstitution. Other steps in the pathway, e.g. conversion of N-methyl-gamm, gamma-dimethylallyltryptophan to chanoclavine I and conversion of elymoclavine to the peptide alkaloids will be investigated for involvement of cytochrome P-450.